This invention relates generally to improvements in water purification systems of the type adapted to provide a supply of purified water for use in drinking, cooking, etc. More particularly, this invention relates to a water purification system designed primarily for household use, and including compact and efficient cooling apparatus for chilling the produced supply of purified water.
Water purification systems in general are relatively well-known in the art for use in producing a supply of purified water from ordinary tap water or the like. Such water purification systems commonly include a reverse osmosis unit having an inlet connected to a tap water supply, wherein the reverse osmosis unit produces two water outflows including a purified water supply and a waste water supply, sometimes referred to as brine, with impurities concentrated therein. In purification systems of this type the production of purified water is normally relatively slow, whereby the purified water outflow is typically coupled to and stored within an appropriate storage tank ready for dispensing when desired through a faucet valve or the like. Such purification systems are normally intended for installation into the cabinet space beneath a standard residential kitchen sink, with the faucet valve mounted on or at the sink in an accessible position ready for use. Examples of water purification systems of this general type are found, for example, by reference to U.S. Pat. Nos. 4,585,554 and 4,595,497.
In some prior art water purification systems of the general type described above, cooling or chilling equipment has been proposed for reducing the temperature of the purified water supply within the storage tank. With such equipment, the purified water can be dispensed at a refrigerated temperature to provide a highly pleasing source of water for drinking and other uses. However, such cooling or chilling equipment has normally included mechanical refrigeration systems which undesirably increase the overall cost, complexity, size, and operational noise of the purification system. Alternate cooling system proposals have suggested the use of relatively compact thermoelectric heat transfer cooling modules, but these proposals have required relatively large surface area heat sinks and/or the use of cooling fans to obtain satisfactory transfer of thermal energy from the purified water supply. The use of large heat sinks and/or cooling fans in a water purification system designed for under-the-sink installation, however, creates significant system size problems as well as undesirable increases in system cost. Moreover, in many instances, the closed nature of the cabinet installation results in significant air flow limitations preventing adequate heat transfer when a cooling fan is used.
There exists, therefore, a significant need for an improved water purification system designed for under-the-sink installation in a compact, space-efficient manner while providing compact and efficient means for chilling a stored supply of purified water. The present invention fulfills these needs and provides further related advantages.